@box:{
    box-sizing: border-box
}
.br(@w){
    border-radius:@w
}
.btn(@bg:#43B2F9, @c:#fff, @h:36px, @b:4px){
    padding:0 20px;
    height:@h;
    line-height: @h;
    color: @c;
    background:@bg ;
    text-align: center;
    border-radius: @b;
    cursor: pointer;
}